Intelligent waveform selection for a welding system having particular electrical output characteristics

ABSTRACT

Systems and methods for selecting a welding output waveform based on characterizing a welding circuit output path with respect to its electrical characteristics. At least one electrical characteristic (e.g., inductance, resistance) of a welding output circuit path connected to a welding power source is determined. A welding output waveform is selected from a plurality of welding output waveforms based on the determined electrical characteristics. As a result, the selected welding output waveform is matched to the welding output circuit path electrical characteristics to provide superior welding performance.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This U.S. patent application is a continuation of pending U.S. patentapplication Ser. No. 13/474,267, filed on May 17, 2012, which isincorporated herein by reference in its entirety. U.S. Pat. No.7,683,290 issued to Daniel et al. on Mar. 23, 2010 is incorporatedherein by reference in its entirety. U.S. Pat. No. 6,730,875 issued toHsu on May 4, 2004 is incorporated herein by reference in its entirety.U.S. Pat. No. 6,596,970 issued to Blankenship et al. on Jul. 22, 2003 isincorporated herein by reference in its entirety.

TECHNICAL FIELD

Certain embodiments of the present invention relate to welding. Moreparticularly, certain embodiments of the present invention relate tosystems and methods for selecting a welding output waveform in responseto characterizing a welding circuit output path with respect to itselectrical characteristics.

BACKGROUND

Welding power sources today use advanced power electronics principlesthat allow for very fast output current changes which can besignificantly affected by the electrical output characteristics of thesystem such as, for example, inductance. As such, welding systems todayare often “tuned down” to perform acceptably within typical operatingscenarios. That is, the welding waveforms are often designed toaccommodate the worst case scenario that is likely to be experienced bythe welding system. However, the window of operation is quite wide andis affected by the length of the welding cable, the type of weldingcable being used, as well as other factors. Therefore, there are timeswhen a “tuned down” welding waveform is being used, even though thesystem could support a higher performing welding waveform. As such,higher welding performance is sacrificed.

Further limitations and disadvantages of conventional, traditional, andproposed approaches will become apparent to one of skill in the art,through comparison of such systems and methods with embodiments of thepresent invention as set forth in the remainder of the presentapplication with reference to the drawings.

SUMMARY

Embodiments of the present invention provide systems and methods forselecting a welding output waveform based on characterizing a weldingoutput circuit path with respect to its electrical characteristics. Atleast one electrical characteristic (e.g., inductance, resistance) of awelding output circuit path connected to a welding power source isdetermined. A welding output waveform is selected from a plurality ofwelding output waveforms based on the determined electricalcharacteristics. The selected welding output waveform may be matched tothe welding output circuit path electrical characteristics to providesuperior welding performance.

One embodiment of the present invention is a method. The method includesdetermining at least one electrical characteristic of a welding outputcircuit path connected to a welding power source, and selecting awelding output waveform from a plurality of welding output waveformsbased on the at least one electrical characteristic. The method mayfurther include having the welding power source apply the selectedwelding output waveform to the welding output circuit path. The at leastone electrical characteristic of the welding output circuit path may bean inductance value of the welding output circuit path, a resistancevalue of the welding output circuit path, or both.

One embodiment of the present invention is a welding power source havinga welding output. The welding power source is configured to determine atleast one electrical characteristic of a welding output circuit pathconnected to the welding output of the welding power source. The weldingpower source is further configured to select a welding output waveformfrom a plurality of welding output waveforms stored in the welding powersource in response to the at least one electrical characteristic. Thewelding power source may also be configured to apply a selected weldingoutput waveform to a welding output circuit path connected to thewelding output of the welding power source. The welding power source mayinclude at least one look-up-table (LUT) configured to map electricalcharacteristics to welding output waveforms. The at least one electricalcharacteristic of the welding output circuit path may be an inductancevalue of the welding output circuit path, a resistance value of thewelding output circuit path, or both.

One embodiment of the present invention is a system. The system includesa welding power source having a welding output. The welding power sourceis configured to store a plurality of welding output waveforms andselect one of the plurality of welding output waveforms based on atleast one electrical characteristic of a welding output circuit pathconnected to the welding output. The system also includes a weldingoutput circuit path operatively connected to the welding output. Thewelding output circuit path may include one or more of a welding cable,a welding tool and/or electrode, and a workpiece and/or workpiececonnector. The welding output circuit path may run from the weldingpower source through the welding cable to the welding tool and/orelectrode, through the workpiece and/or workpiece connector, and backthrough the welding cable to the welding power source. The systemfurther includes a welding output analyzer operatively connected to oneof the welding output circuit path or the welding power source. Thewelding output analyzer is configured to monitor welding outputelectrical parameters applied to the welding output circuit path by thewelding power source, determine at least one electrical characteristicof the welding output circuit path based on the welding outputelectrical parameters, and provide the at least one electricalcharacteristic to the welding power source. The welding power source mayinclude at least one look-up table (LUT) configured to map electricalcharacteristics to welding output waveforms. The welding outputelectrical parameters may include at least one regulated welding outputcurrent and a resulting welding output voltage. The welding outputelectrical parameters may include at least one regulated welding outputvoltage and a resulting welding output current. The at least oneelectrical characteristic of the welding circuit output path may includean inductance, a resistance, or both.

One embodiment of the present invention is a system. The system includesmeans for monitoring welding output electrical parameters applied to awelding output circuit path by a welding power source. The system alsoincludes means for determining at least one electrical characteristic ofthe welding output circuit path based on the welding output electricalparameters. The system further includes means for selecting a weldingoutput waveform, to be applied to the welding output circuit path by thewelding power source, in response to the at least one electricalcharacteristic.

Details of illustrated embodiments of the present invention will be morefully understood from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic block diagram of a first exemplaryembodiment of a welding system including a welding output circuit path;

FIG. 2 is an exemplary circuit representation of the welding outputcircuit path of FIG. 1, in accordance with an embodiment of the presentinvention;

FIG. 3 is an exemplary graph showing how the total inductance L_(T) ofthe welding output circuit path represented in FIG. 2 can change as afunction of current I through the circuit path, in accordance with anembodiment of the present invention;

FIG. 4 is a flowchart of an exemplary embodiment of a method formatching a welding output waveform to a welding output circuit path;

FIG. 5 illustrates a schematic block diagram of a look-up-table, inaccordance with an embodiment of the present invention; and

FIG. 6 illustrates a schematic block diagram of a second exemplaryembodiment of a welding system including a welding output circuit path.

DETAILED DESCRIPTION

The following are definitions of exemplary terms that may be used withinthe disclosure. Both singular and plural forms of all terms fall withineach meaning:

“Software” or “computer program” as used herein includes, but is notlimited to, one or more computer readable and/or executable instructionsthat cause a computer or other electronic device to perform functions,actions, and/or behave in a desired manner. The instructions may beembodied in various forms such as routines, algorithms, modules orprograms including separate applications or code from dynamically linkedlibraries. Software may also be implemented in various forms such as astand-alone program, a function call, a servlet, an applet, anapplication, instructions stored in a memory, part of an operatingsystem or other type of executable instructions. It will be appreciatedby one of ordinary skill in the art that the form of software isdependent on, for example, requirements of a desired application, theenvironment it runs on, and/or the desires of a designer/programmer orthe like.

“Computer” or “processing element” as used herein includes, but is notlimited to, any programmed or programmable electronic device that canstore, retrieve, and process data. “Non-transitory computer-readablemedia” include, but are not limited to, a CD-ROM, a removable flashmemory card, a hard disk drive, a magnetic tape, and a floppy disk.

The term “welding output waveform”, as used herein, can mean the data orinformation that represents the time varying shape to be applied towelding output voltages or currents over time, and/or the actualcurrents or voltages applied to a welding output circuit path by awelding power source over time.

The term “welding output”, as used herein, means the circuitryassociated with the electrical welding output of a welding power sourcewhich is configured to be operatively connected to one or more weldingcables.

The terms “welding tool”, “welding electrode”, and “welding wire” may beused interchangeably herein.

FIG. 1 illustrates a schematic block diagram of an exemplary embodimentof a welding system 100 including a welding output circuit path 105, inaccordance with various aspects of the present invention. The weldingsystem 100 includes a welding power source 110 having a welding output112 and, optionally, a display 115. The welding output circuit path 105is connected to the welding power source 110 at the welding output 112.

In accordance with an embodiment, the welding output circuit path 105includes a welding cable 120, a welding tool 130, a workpiece connector150, a spool of welding wire 160, a welding wire feeder 170, a weldingwire 180, and an optional workpiece 140. The welding wire 180 is fedinto the welding tool 130 from the spool 160 via the wire feeder 170, inaccordance with an embodiment. In accordance with another embodiment,the welding system 100 does not include a spool of wire 160, a wirefeeder 170, or a welding wire 180 but, instead, includes a welding toolcomprising a consumable electrode such as is used in, for example, stickwelding. In accordance with various embodiments of the presentinvention, the welding tool 130 may include at least one of a weldingtorch, a welding gun, an electrode holder, and a welding consumable.

The welding output circuit path 105 runs from the welding output 112 ofthe welding power source 110 through the welding cable 120 to thewelding tool 130, through the workpiece 140 and/or to the workpiececonnector 150, and back through the welding cable 120 to the weldingpower source 110. During operation, the welding power source 110 mayapply a welding output waveform to the welding output circuit path 105,causing a time-varying electrical current to run through the weldingoutput circuit path 105 and creating an arc between the wire (orelectrode) and the workpiece 140. In accordance with an embodiment ofthe present invention, the welding cable 120 comprises a coaxial cableassembly. In accordance with another embodiment of the presentinvention, the welding cable 120 comprises a first cable length runningfrom the welding power source 110 to the welding tool 130, and a secondcable length running from the workpiece connector 150 to the weldingpower source 110.

In accordance with various embodiments of the present invention, theworkpiece 140 may or may not be present as part of the welding outputcircuit path 105. If the workpiece 140 is not present, the welding tool130 may be connected directly to the workpiece connector 150. If theworkpiece 140 is present, the workpiece connector 150 may be connectedbetween the workpiece 140 and the welding cable 120. The welding tool130 may be directly touching the workpiece 140, or an arc 190 may bepresent between the welding tool 130 and the workpiece 140, for example,as during a welding operation. Also, the part of the welding wire 180actually going through the welding tool 130 may be considered part ofthe welding output circuit path 105, for example, during a weldingoperation.

FIG. 2 is an exemplary circuit representation 200 of the welding outputcircuit path 105 of FIG. 1, in accordance with an embodiment of thepresent invention. The circuit representation 200 includes an inductanceL_(c) 210 and a resistance R_(c) 220 of the welding cable 120 side ofthe welding output circuit path 105. The circuit representation 200 alsoincludes an inductance L_(m) 230, an internal resistance R_(i) 240, anda diode D₁ 250 of the welding power source 110 side (machine side) ofthe welding output circuit path 105. The welding cable 120 connects tothe welding power supply 110 at the welding output 112 having electricalnodes 260 and 270.

When a current (I) 280 flows through the welding output circuit path105, an output voltage (V) 265 is produced between the nodes 260 and 270and the resistances R_(c) and R_(i) and the diode D₁ help to dissipateenergy from the inductors L_(c) and L_(m). In accordance with otherembodiments of the present invention, other dissipating components maybe present in the circuit representation 200 as well such as, forexample, a switch (not shown). Such energy-dissipating components aretaken into consideration when trying to accurately determine the totalinductance L_(T)=L_(m)+L_(c) of the welding output circuit path 105.

FIG. 3 is an exemplary graph 300 showing how the total inductance L_(T)of the welding output circuit path 105 represented in FIG. 2 can changeas a function of current (I) through the circuit path, in accordancewith an embodiment of the present invention. A first curve 310 ofinductance (L) versus current (I) is shown for a relatively long weldingcable, and a second curve 320 of inductance (L) versus current (I) isshown for a relatively short welding cable. Both curves are relativelyflat from about 150 amps to 300 amps as shown in the graph 300. As aresult, the process of determining the total inductance L_(T) and thetotal resistance R_(T) (i.e., the electrical characteristics of thewelding output circuit path) is typically conducted over the flat region330 (e.g., between 150 and 300 amps).

U.S. Pat. No. 7,683,290, which is incorporated herein by reference,describes how the electrical characteristics (e.g., inductance andresistance) of a welding output circuit path may be determined. Forexample, in accordance with an embodiment of the present invention, thewelding power source 110 is able to check its output circuit anddetermine the resistance and inductance without the use of externalinstruments. Measurements may be performed with the welding tool 130short-circuited to the workpiece 140, or measurements may be performedduring a welding process when an arc 190 is formed between the weldingtool 130 and the workpiece 140.

In accordance with an embodiment, an inductance measurement technique isbuilt into the welding power source 110. First, the output current isregulated to a known value while the output voltage is measured.Alternatively, the voltage may be regulated and the resulting currentmeasured. From such current and voltage, the resistance of the weldingoutput circuit path may be calculated as:R=V/I,where R is resistance, V is voltage, and I is current.

Next, the power source is turned off and the current decay is measured.Inductance is then estimated by the equation given here as:L=−(R*t)/(ln[i(t ₁)/i(t ₀)]),

-   -   where i(t₀) is the current measured at time t₀,    -   i(t₁) is the current measured at time t₁, and    -   t=t₁−t₀.

Such an estimate of inductance L is only a rough approximation since theestimate assumes that all of the energy in the inductance is dissipatedin the resistance R. However, in reality, some of the energy is beingdissipated by other components as well such as, for example, diodes andswitches within the welding power source. Other more accuratecalculation methods are possible as well, in accordance with variousother embodiments of the present invention, as described in U.S. Pat.No. 7,683,290.

FIG. 4 is a flowchart of an exemplary embodiment of a method 400 formatching a welding output waveform to a welding output circuit path. Instep 410 of the method 400, at least one electrical characteristic of awelding output circuit path connected to a welding power source isdetermined. For example, the electrical characteristics may bedetermined automatically by the welding power source 110. In step 420 ofthe method 400, a welding output waveform is selected from a pluralityof welding output waveforms based on the at least one electricalcharacteristic. For example, the welding output waveform may be selectedautomatically by the welding power source 110 using a look-up table or astate table. In step 430 of the method 400, the welding power sourceapplies the selected welding output waveform to the welding outputcircuit path (for example, at the command of the user).

As an example, a user may desire to perform a welding operation with thesystem 100 of FIG. 1. The user may desire to perform a high switchingspeed welding operation, including implementing the method 400 of FIG.4. The high switching speed welding operation is intended to switch fromlow output current levels to high output current levels in a weldingoutput waveform, and vice versa, over relatively short intervals oftime. For example, a welding power source may be configured to operateat a maximum switching speed of 1 kHz to facilitate such high speedcurrent switching. However, the effective speed of switching (and thelengths of rise and fall times associated with the switching currents)may be limited by the electrical characteristics of the welding outputcircuit path 105.

In an ideal situation with unlimited rise and fall rates (e.g., havingabsolutely no inductance in the welding output circuit path), thewelding output current may be able to change over a range of 3000 ampsin one millisecond. However, in the real world, there are always someinductances and resistances associated with the welding output circuitpath which limit the rise and fall times of the output current. Forexample, higher levels of resistance may be present due to frayed leadson a welding cable, an undersized welding cable, or a very long weldingcable. The electrical characteristics of the welding output circuit pathaffect the characteristics of the resulting arc during welding which canaffect the quality of the resulting weld.

Continuing with the example, the user may initially leave the weldingpower source 110 at a remote distance from the workpiece 140 and run arelatively long welding cable 120 from the welding power source 110 tothe workpiece 140. The user selects a high switching speed weldingprocess and the system 100 determines the electrical characteristics ofthe welding output circuit path 105. Due to the relatively long weldingcable 120, the system 100 determines that the inductance and resistanceare relatively high. Even though the user has selected a high switchingspeed welding process, the system 100 selects a first welding outputwaveform, from a plurality of possible welding output waveformsassociated with the high switching speed welding process, that will workwell with the relatively high inductance and resistance caused by therelatively long welding cable 120. That is, the switching speeds of thefirst selected welding output waveform are compatible with the rise timeand fall time limits that the relatively high inductance and resistanceof the welding output circuit path impose. As a result, the userproceeds to produce a first weld having acceptable quality.

Later, the user desires to weld another workpiece 140 which is locatedmuch closer to the welding power source 110. The user replaces therelatively long welding cable 120 with a much shorter welding cable. Theuser selects the same high switching speed welding process as before andthe system 100 determines the electrical characteristics of the shorterwelding output circuit path 105. The system 100 now determines that theinductance and resistance of the welding output circuit path are muchlower than before, and the system selects a second welding outputwaveform, from the plurality of possible welding output waveformsassociated with the high switching speed welding process, having higherswitching speeds. That is, the switching speeds of the second selectedwelding output waveform are compatible with the faster rise and falltime limits that the relatively low inductance and resistance of thewelding output circuit path impose.

As a result, the user proceeds to produce a second weld having certainquality characteristics that are even better than those of the firstweld due to being able to take advantage of the higher switching speedsat the lower inductance and resistance levels.

In accordance with an embodiment, the determination of the electricalcharacteristics and the selection of the welding output waveforms areperformed automatically by the welding power source 110, without theuser having to think about it or do anything special.

In accordance with an embodiment of the present invention, the systemmay indicate to the user when an “inferior” welding output waveform hasbeen selected, due to the limiting electrical characteristics of thewelding output circuit path. Such an indication may be provided on adisplay 115 of the welding power source, for example. Furthermore, suchan indication may incentivize the user to check and/or change the set upof the welding output circuit path. Also, there may be times when a userselects a welding process, or even a specific welding waveform, that isincompatible with the present welding output circuit path. In such ascenario, the system may provide an indication of the incompatibility tothe user on a display 115 of the welding power source, incentivizing theuser to select a new process or waveform, or change the set up of thewelding output circuit path.

FIG. 5 illustrates a schematic block diagram of a look-up-table 500, inaccordance with an embodiment of the present invention. The look-uptable (LUT) 500 is implemented in the welding power source 110, inaccordance with an embodiment and maps one or more inputs to an output.The inputs of the LUT 500 are the determined electrical characteristics(e.g., inductance and/or resistance) of the welding output circuit path105, and the output is a welding output waveform, or waveform identifierthat identifies a particular welding output waveform, of a plurality ofwelding output waveforms stored (e.g., in a computer memory) in thewelding power source 110.

For example, a particular welding process or mode (e.g., a highswitching speed process) may have ten welding output waveformsassociated with it in the welding power source 110. A user may select awelding process and the welding power source 110 may automaticallydetermine, via the LUT 500, the appropriate waveform to select from theten waveforms, after automatically determining the electricalcharacteristics of a connected welding output circuit path 105. The LUT500 is configured a priori to associate an appropriate waveform with aparticular combination of inductance and resistance (or with aparticular range of inductances and range of resistances).

In accordance with various embodiments, the LUT 500 may be implementedin hardware as, for example, an EEPROM, or in software as an addressabledata structure stored in computer memory, for example. Other hardwareand software constructs may be possible as well. In accordance with anembodiment of the present invention, the system 100 includes a pluralityof LUTs 500. For example, the welding power source 110 may have one LUTfor each welding process or welding mode provided by the welding powersource 110.

FIG. 6 illustrates a schematic block diagram of a second exemplaryembodiment of a welding system 600 including a welding output circuitpath 105. Similar to the system 100 of FIG. 1, the welding system 600includes a welding power source 610 having a welding output 112. Thewelding output circuit path 105 is connected to the welding power source610 at the welding output 112. The system 600 also includes a weldingoutput analyzer 620. In accordance with an embodiment, the weldingoutput analyzer 620 is a computer that operatively interfaces with thewelding power source 610 and/or the welding output circuit path 105.

In the system 600 of FIG. 6, the functionality of determining theelectrical characteristics of the welding output circuit path 105 andselecting a welding output waveform based on the determined electricalcharacteristics is implemented in the welding output analyzer 620. Forexample, the welding output analyzer 620 may command the welding powersource 610 to apply welding output electrical parameters (e.g.,regulated output voltages or currents) to the welding output circuitpath 105 and measure the resulting welding output electrical parameters(e.g., output currents or output voltages). The welding outputelectrical parameters may be communicated from the welding power source610 to the welding output analyzer 620 where the welding output analyzer620 proceeds to compute the electrical characteristics (e.g., resistanceand inductance) of the welding output circuit path 105 based on thewelding output electrical parameters. In accordance with an alternativeembodiment, the welding output analyzer 620 may monitor the weldingoutput electrical parameters by direct measurement at the welding outputcircuit path 105, for example, via a high impedance interface and/or acurrent shunt.

The welding output analyzer 620, having a LUT 500, may then proceed toselect an appropriate welding output waveform based on the computedelectrical characteristics and communicate the selected welding outputwaveform to the welding power source 610. The welding power source 610may then apply the selected welding output waveform to the weldingoutput circuit path (for example, at the command of the user). Inaccordance with various embodiments, the electrical characteristics ofthe welding output circuit path may be determined automatically by thewelding output analyzer 620, or in a manual manner with a user operatingthe welding output analyzer 620. For a manual scenario, the weldingoutput analyzer 620 may optionally include a user interface 626 and/or adisplay 625 to aid the user.

In accordance with other alternative embodiments, the various functionalaspects of determining the electrical characteristics of a weldingoutput circuit path and selecting a welding output waveform based on theelectrical characteristics may be distributed between the welding powersource and the welding output analyzer in various ways, dependent onprudent design judgment, cost restrictions, and/or other considerationsand tradeoffs.

In summary, systems and methods for selecting a welding output waveformbased on characterizing a welding output circuit path with respect toits electrical characteristics are disclosed. At least one electricalcharacteristic (e.g., inductance, resistance) of a welding outputcircuit path connected to a welding power source is determined. Awelding output waveform is selected from a plurality of welding outputwaveforms based on the determined electrical characteristics. As aresult, the selected welding output waveform is matched to the weldingoutput circuit path electrical characteristics to provide superiorwelding performance.

In appended claims, the terms “including” and “having” are used as theplain language equivalents of the term “comprising”; the term “in which”is equivalent to “wherein.” Moreover, in appended claims, the terms“first,” “second,” “third,” “upper,” “lower,” “bottom,” “top,” etc. areused merely as labels, and are not intended to impose numerical orpositional requirements on their objects. Further, the limitations ofthe appended claims are not written in means-plus-function format andare not intended to be interpreted based on 35 U.S.C. § 112, sixthparagraph, unless and until such claim limitations expressly use thephrase “means for” followed by a statement of function void of furtherstructure. As used herein, an element or step recited in the singularand proceeded with the word “a” or “an” should be understood as notexcluding plural of said elements or steps, unless such exclusion isexplicitly stated. Furthermore, references to “one embodiment” of thepresent invention are not intended to be interpreted as excluding theexistence of additional embodiments that also incorporate the recitedfeatures. Moreover, unless explicitly stated to the contrary,embodiments “comprising,” “including,” or “having” an element or aplurality of elements having a particular property may includeadditional such elements not having that property. Moreover, certainembodiments may be shown as having like or similar elements, however,this is merely for illustration purposes, and such embodiments need notnecessarily have the same elements unless specified in the claims.

As used herein, the terms “may” and “may be” indicate a possibility ofan occurrence within a set of circumstances; a possession of a specifiedproperty, characteristic or function; and/or qualify another verb byexpressing one or more of an ability, capability, or possibilityassociated with the qualified verb. Accordingly, usage of “may” and “maybe” indicates that a modified term is apparently appropriate, capable,or suitable for an indicated capacity, function, or usage, while takinginto account that in some circumstances the modified term may sometimesnot be appropriate, capable, or suitable. For example, in somecircumstances an event or capacity can be expected, while in othercircumstances the event or capacity cannot occur—this distinction iscaptured by the terms “may” and “may be.”

This written description uses examples to disclose the invention,including the best mode, and also to enable one of ordinary skill in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to one of ordinary skill in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differentiate from the literal language of theclaims, or if they include equivalent structural elements withinsubstantial differences from the literal language of the claims.

While the claimed subject matter of the present application has beendescribed with reference to certain embodiments, it will be understoodby those skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope of theclaimed subject matter. In addition, many modifications may be made toadapt a particular situation or material to the teachings of the claimedsubject matter without departing from its scope. Therefore, it isintended that the claimed subject matter not be limited to theparticular embodiments disclosed, but that the claimed subject matterwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A welding method comprising the steps of:estimating an inductance value of a welding output circuit pathconnected to a welding power source; and applying, by the welding powersource, a welding output waveform to the welding output circuit pathbased upon the inductance value, wherein the welding output waveform iscompatible with rise and fall time limits of the welding output circuitpath.
 2. The welding method of claim 1, further comprising the step ofdetermining a resistance value of the welding output circuit path,wherein the welding output waveform applied to the welding outputcircuit path is further based upon the resistance value.
 3. The weldingmethod of claim 2, wherein the step of determining the resistance valueincludes applying a regulated voltage signal to the welding outputcircuit path.
 4. The welding method of claim 2, wherein the step ofdetermining the resistance value includes applying a regulated currentsignal to the welding output circuit path.
 5. The welding method ofclaim 1, wherein the step of applying includes adjusting a weldingoutput waveform switching speed based upon the inductance value.
 6. Thewelding method of claim 1, wherein the welding power sourceautomatically performs the step of estimating the inductance value ofthe welding output circuit path.
 7. The welding method of claim 1,wherein the inductance value of the welding output circuit path is atleast in part dependent on a welding cable in the welding output circuitpath.
 8. The welding system of claim 1, wherein the welding power sourceincludes a look-up table that maps the inductance value to the weldingoutput waveform.
 9. A welding system, comprising: a welding power sourcehaving a welding output; and a welding output circuit path connected tothe welding output, wherein the welding power source automaticallyestimates an inductance value of the welding output circuit path, andapplies a welding output waveform to the welding output circuit pathbased upon the inductance value, and wherein the welding output waveformis compatible with rise and fall time limits of the welding outputcircuit path.
 10. The welding power source of claim 9, wherein thewelding power source determines a resistance value of the welding outputcircuit path, and applies the welding output waveform to the weldingoutput circuit path based upon the resistance value.
 11. The weldingpower source of claim 10, wherein the welding power source applies aregulated voltage signal to the welding output circuit path to determinethe resistance value.
 12. The welding power source of claim 10, whereinthe welding power source applies a regulated current signal to thewelding output circuit path to determine the resistance value.
 13. Thewelding power source of claim 9, wherein the welding power sourceadjusts a welding output waveform switching speed based upon theinductance value.
 14. The welding power source of claim 9, wherein thewelding output circuit path includes a welding cable, and the inductancevalue of the welding output circuit path is at least in part dependenton a length of the welding cable.
 15. The welding power source of claim9, wherein the welding power source includes a look-up table that mapsthe inductance value to the welding output waveform.
 16. A weldingsystem, comprising: a welding power source having a welding output; anda welding output circuit path connected to the welding output, whereinthe welding output circuit path includes a welding tool, and a weldingcable extending between the welding output and the welding tool, whereinthe welding power source automatically estimates an inductance value ofthe welding output circuit path, and applies a welding output waveformto the welding output circuit path based upon the inductance value, andwherein the welding output waveform is compatible with rise and falltime limits of the welding output circuit path.
 17. The welding powersource of claim 16, wherein the welding power source includes a look-uptable that maps the inductance value to the welding output waveform. 18.The welding power source of claim 16, wherein the welding power sourcedetermines a resistance value of the welding output circuit path. 19.The welding power source of claim 16, wherein the welding power sourceapplies a regulated voltage signal to the welding output circuit path todetermine the resistance value.
 20. The welding power source of claim16, wherein the welding power source applies a regulated current signalto the welding output circuit path to determine the resistance value.21. The welding power source of claim 16, wherein the welding powersource adjusts a welding output waveform switching speed based upon theinductance value.